Datasheet

Electrical Specifications
26 Datasheet
.
2.7.3.1 GTL+ Front Side Bus Specifications
In most cases, termination resistors are not required as these are integrated into the
processor silicon. See Table 9 for details on which GTL+ signals do not include on-die
termination.
Valid high and low levels are determined by the input buffers by comparing with a
reference voltage called GTLREF. Table 14 lists the GTLREF specifications. The GTL+
reference voltage (GTLREF) should be generated on the system board using high
precision voltage divider circuits.
Table 13. CMOS Signal Group DC Specifications
Symbol Parameter Min Max Unit Notes
1
NOTES:
1. Unless otherwise noted, all specifications in this table apply to all processor frequencies.
V
IL
Input Low Voltage -0.10 V
TT
* 0.30 V
2, 3
2. V
IL
is defined as the voltage range at a receiving agent that will be interpreted as a logical low
value.
3. The V
TT
referred to in these specifications refers to instantaneous V
TT
.
V
IH
Input High Voltage V
TT
* 0.70 V
TT
+ 0.10 V
4, 5, 3
4. V
IH
is defined as the voltage range at a receiving agent that will be interpreted as a logical high
value.
5. V
IH
and V
OH
may experience excursions above V
TT
. However, input signal drivers must comply
with the signal quality specifications.
V
OL
Output Low Voltage -0.10 V
TT
* 0.10 V
3
V
OH
Output High Voltage 0.90 * V
TT
V
TT
+ 0.10 V
6, 5, 3
6. All outputs are open drain.
I
OL
Output Low Current 1.70 4.70 mA
3, 7
7. I
OL
is measured at 0.10 * V
TT.
I
OH
is measured at 0.90 * V
TT.
I
OH
Output High Current 1.70 4.70 mA
3, 7
I
LI
Input Leakage Current N/A ± 100 µA
8
8. Leakage to V
SS
with land held at V
TT
.
I
LO
Output Leakage Current N/A ± 100 µA
9
9. Leakage to V
TT
with land held at 300 mV.